1. Field of the Invention
This invention relates to a method of, and an apparatus for, forming a film of diamond on a substrate by vapor deposition.
2. Description of the Related Art
According to recently known methods for the synthesis of diamond by low-pressure chemical vapor deposition (CVD), a gaseous mixture of a hydrocarbon, or organic compound containing nitrogen, oxygen, etc., and hydrogen is excited by a hot filament, a microwave, high-frequency, or direct current (DC)-discharge plasma, a DC arc discharge, etc. Japanese Patent Application Laid-Open No. 282193/1989 discloses a method which causes diamond to be deposited on a substrate placed in the incomplete combustion region of an oxy-acetylene flame which is called an acetylene feather.
The burner which is employed by these methods, however, produces a conical flame which fails to give a gas stream having a uniform temperature distribution. The resulting active seeds lack uniformity in density and fail to form a homogeneous film of diamond.